<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<div id="app">
    <input type="text" v-model="message">
    {{ message }}<br>
    <login :message="message"></login>
</div>

<script src="../node_modules/vue/dist/vue.min.js"></script>
<script>
    var login = {
        template : '<h1>message: {{ message }}</h1>',
        props : ['message']
    }
    var vm = new Vue({
        el : '#app',
        data : {
            message : '123'
        },
        components : {
            login
        }
    })
</script>
</body>
</html>